Locomotive firebox



A ril 5, 1938. G. J. CHRISTENS ON 2,112,954

LOCOMOTIVE FIREBOX Filed June 13, 1956 fizzy-W.- 4

Patented Apr. 5, 1938 UNITED STATES ATENT OFFICE Locomotive FireboxCompany,

Chicago, 111.,

a corporation of Delaware Application June 13, 1936, Serial No. 85,064

8 Claims.

This invention relates to improvements in locomotive fireboxes and itconsists of the matters hereinafter described and more particularlypointed out in the appended claims.

This invention is more particularly concerned with fireboxes equippedwith a thermic syphon, of the type which is a substantially rigid water,steaming and circulating element that opens at its ends through certainsheets of the firebox at different elevations, for the purpose ofincreasing the effective heating surface area of the firebox whereby abetter water steaming and circulating action is possible.

One of the objects of the present invention is to provide means in asyphon equipped firebox whereby additional water steaming andcirculating efiiciency and a better support for the arch brick isobtained.

Another object of the invention is to provide a firebox of this kind,wherein water is taken from the front throat and at points along eachside water leg and is discharged above the crown sheet at pointstherealong in a manner assuring a continuous flooding of the same withwater, even though the water level in the boiler falls below normal.

A further object of the invention is to provide a tube arrangement in alocomotive type of firebox, which coacts with the syphon in forming abetter support for the brick of the arch and at the same time employslonger tubes of a peculiar shape that gives them more flexibility toaccommodate sheet movement.

The above mentioned objects of the invention as well as others, togetherwith the advantages thereof, will more fully appear as the specificationproceeds.

In the drawing:

Fig. l is a longitudinal vertical sectional View through a locomotiveboiler embodying the preferred form of the invention.

Fig. 2 is a transverse vertical sectional View through the same as takenon the line 2-2 of Fig. 1.

Fig. 3 is another and fragmentary transverse vertical detail sectionalView through a part of the firebox as taken on the line 3-45 of Fig. 1.

Referring now in detail to that embodiment of the invention illustratedin the accompanying drawing, 55 indicate the side sheets of the firebox,and 6 indicates the crown-sheet thereof. 1 indicates the front or fluesheet thereof and 8 indicates the back sheet thereof. It will beunderstood that the firebox is positioned in the rear end of the boilershell, which includes the outer side sheets 9-9, top sheet I0, backsheet II and front throat sheet 12. Portions of the back sheets 8 and I1 respectively are formed to provide a fuel door opening l3.

Several of the sheets mentioned coact to form the side water legs l4,back water leg I5 and front throat IS respectively, all bottomed by amud ring ll. The above is typical of a conventional locomotive boilerrear end structure and requires no further description except to saythat companion sheets are suitably stay-bolted.

The firebox herein shown is equippedwith a socalled thermic syphon I8which is a substantially rigid but hollow Water steaming and circulatingelement having ends that open through certain sheets of the firebox atdifferent elevations. When a plurality of such syphons are employed inthe firebox, they are spaced laterally from each other.

In the present instance, only one syphon is employed and this isdisposed in the longitudinal medianplane of the firebox. Such a syphonin this instance includes a substantially flat, triangularly shaped bodyl9 having an outwardly flared flange 2|! at the top that fits and iswelded in a longitudinally extending elongated opening in the crownsheet. This body has an inclined bulged bottom 2! which extendsdownwardly and forwardly to terminate in a tubular inlet neck extension22 that opens through the bottom portion of the front sheet I so as tocommunicate with the front throat H3. The body which is closed at itsfront and rear ends is suitably staybolted to resist internal pressures.t is apparent that the syphon presents a considerable surface area. Inthe operation of the boiler in which the syphon is installed, water isdrawn in from the throat l6 and a part thereof is generated into steam,the steam and hot water being discharged into the boiler water and steamspace of the boiler above the crown sheet. In this discharge of water,the same operates to flood the crown sheet. By reason of the differencein thermic heads, a vigorous water circulating action is established inthe boiler.

The syphon described, substantially divides the firebox longitudinallyinto two laterally spaced combustion chambers or passages both of whichcommunicate with the flues of the boiler. In each chamber or passage isa set of circulator tubes 23, each comprising a plurality. oflongitudinally spaced tube elements, the elements in one set' on oneside of the syphon being arranged in the transverse plane of theelfimfints of the other set.

Each tube element includes an inlet portion 24, an outlet portion 25 andintermediate connecting portion 25 of reverse curve formation on theorder of an ogee or bulge. The inlet portion has an extremity 2'!arranged at a right angle to the plane of the associated side sheet.This extremity which extends at a right angle to the plane of the sidesheet is fixed in said side sheet and merges into the inlet portion 24by a short curved portion 28. The inlet portion 24 extends upwardly andinwardly from the curved portion 28 at an angle which corresponds to theangle of transverse inclination of one side of the arch which will bereferred to later. The crown sheet 6 is arched or curved transversely ofthe firebox and the outlet portion 25 of the tube extends radially withrespect thereto and opens through and is fixed in any suitable manner insaid crown sheet.

As herein shown, the intermediate portion 26 of each tube element 23comprises upper and lower reversed curved parts and the lower part is sodisposed as to be spaced substantially close to the associated side ofthe syphon body. The tube elements in each set are of successivelyincreasing heights, from the rear to the front of the firebox. Thisdifierence in heights is such that a line extending between the pointswhere the inlet portions of the tube elements in each set, open throughthe associated side sheet, is disposed in an inclined planesubstantially conforming to the plane of inclination of the bulgedbottom 22 of the syphon body and its neck extension.

The structure described is admirably adapted) to the support of an archindicated as a whole as at 29 in Fig. 2. This arch is made of transverserows of brick, each including an outer end brick 30, an inner end brick3| and intermediate brick 32. The outer end and intermediate brick 3 and32 are curved transversely of the plane of the respective row while theinner end brick is fiat. The outer end and intermediate brick each has aconcaved corner to rest upon upper parts of the inlet portions of thetubes. The outer end of the outer brick in each row engages against theassociated side sheet. The inner end of each inner end brick is cut awayto permit it to pass the curved parts 26 of the tubes. Furthermore, theinner end of each inner end brick is formed with a shoulder to engageupon the body bottom bulge 2! and inlet neck 22, respectively.

In the outer side sheets 9 of the boiler in line with the inlet endextremity 21 of the various tube elements, are wash-out plugs 33 and inthe top sheet it) of the boiler shell are wash-out plugs 34 in line withthe outlet ends of the various circulator tube elements 23.

In the operation of the boiler of which the fixebox forms a part, thesyphon operates to take in boiler water from the front throat and todischarge it out through its top end, thus keeping the crown sheetflooded with water. Also, due to the presence of the sets or banks ofcirculator tubes, water enters the inlet ends of the various tubeelements at spaced points along each side water leg l4. Under the actionof heat transfer from the products of combustion to the water in thetube elements 23, a part of the water is generated into steam to passinto the boiler above the water therein and the remainder of said wateris discharged out through the outlet ends to assist the syphon inkeeping the crown sheet flooded to increase the safety factor under lowwater conditions.

As water is taken into the various tube elements 23 from longitudinalspaced points in each water leg, a continuous and vigorous circulationis established in the side water legs which washes the water side of thesheets clean of any solids tending to adhere thereto. Also due to theturbulence set up by the circulating action, the solids remain insuspension and cannot readily settle out to accumulate as a mud upon themud ring which bottoms the various water legs.

By reason of the circulation thus produced through the side Water legs,the expansion and contraction stresses in the firebox sheets areequalized and the life of the same is greatly increased.

The tube elements 23 are preferably made of seamless tubing and may bereadily bent to shape. As the curves therein are of a relatively largeradius, the danger of cracking in shaping the tubes is avoided. Also,such curves permit a ready wash-out of the tubes.

Cross reference is hereby made to applicants co-pending application S.N. 85,063 which claims certain of the subject matter herein disclosed,but not claimed herein.

While in describing the invention, I have referred in detail to theform, arrangement and construction of the parts thereof, this is to beconsidered only in the illustrative sense so that I do not wish to belimited thereto except as may be specifically set forth in the appendedclaims.

I claim as my invention:

1. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a substantially rigid water steaming and circulatingelement in the firebox having ends which open through certain of thesheets of the firebox at different elevations, and a circulator tubearranged on each side of said element and extending transversely of thefire box, each tube including an inlet portion opening through anassociated side sheet and an outlet portion opening through the crownsheet and a reversely curved intermediate portion connecting said inletand outlet portions, said reversely curved portions being arrangedrelatively close to the sides of said element and being spaced closertogether than the outlet portions of both tubes where they open throughthe crown sheet.

2. A locomotive firebox embodying therein a crown sheet, a front throatand side sheets, a substantially rigid water steaming and circulatingelement in the median plane of the firebox having ends which openthrough certain of the sheets of the firebox at difierent elevations,sets of circulator tubes in and arranged transversely of the firebox,with one set arranged on each side of the water steaming and circulatingelement and each set comprising a plurality of tube elements arranged intransverse planes, spaced longitudinally of the firebox, each tubecomprising an inlet portion opening through an associated side sheet andan outlet portion opening through the crown sheet and a reversely curvedintermediate portion connecting said inlet and outlet portions, thereversely curved portions of the tubes in each set being arrangedsubstantially close to the sides of said element, said last mentionedportions of the tubes in both sets being spaced closer together than theoutlet portions of the tubes in both sets where they open through thecrown sheet.

3. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a substantially rigid water steaming and circulatingelement in the median plane of the firebox having ends which openthrough certain of the sheets of the firebox at different elevations,sets of circulator tubes in the firebox, with one set arranged on eachside of the water steaming and circulating element and each setcomprising a plurality of tube elements arranged in transverse planesspaced longitudinally of the firebox, each tube comprising an inletportion opening through an associated side sheet and an outlet portionopening through the crown sheet and a curved intermediate portionconnecting said inlet and outlet portions, and a fire arch composed ofbrick supported in part by said water steaming and circulating elementand in part by said circulator tubes.

4. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a substantially rigid water steaming and circulatingelement in the median plane of the firebox having ends which openthrough certain of the sheets of the firebox at different elevations,sets of circulator tubes in the firebox, with one set arranged on eachside of the water steaming and circulating element and each setcomprising a plurality of tube elements arranged in transverse planesspaced longitudinally of the firebox, each tube comprising an inletportion opening through an associated side sheet and an outlet portionopening through the crown sheet and a curved intermediate portionconnecting said inlet and outlet portions, and transverse rows of firebrick between and supported at least in part on the inlet portions ofadjacent tube elements in each set and closing the space between thesides of said water steaming and circulating element and the respectiveside sheets.

5. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a substantially rigid water steaming and circulatingelement arranged longitudinally of the firebox and having ends whichopen through certain of the sheets of the firebox at differentelevations, a. set of circulator tubes arranged in and extendingtransversely of the firebox on each side of the water steaming andcirculating element, each set of tubes comprising a plurality of tubeelements arranged in transverse planes spaced longitudinally of thefirebox, each tube comprising an inlet portion opening through the sidesheets, an outlet portion opening through the crown sheet and areversely curved intermediate portion connecting said inlet and outletportions, and means providing arch portions between both sides of saidelement and said side sheets, said arch portions comprising bricks,certain ones of which are supported solely upon said inlet portions ofsaid tubes and others of which are supported jointly upon said inletportions and upon portions of said element.

6. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a water steaming and circulating element in the fireboxand including a flat hollow body arranged longitudinally of the fireboxand opening through the crown sheet, said body having a downwardly andforwardly inclined bulged bottom that merges into a tubular neck whichopens through the throat sheet of the firebox, a set of circulator tubesarranged in and extending transversely of the firebox on each side ofthe water steaming and circulating element, each set comprising aplurality of tube elements arranged in transverse planes spacedlongitudinally of the firebox, each tube including an inlet portion, theinlet portions of all the tubes in each set opening through theassociated side sheet in a plane substantially corresponding to theplane of the inclination of the bottom of the said body and its neckextension, each tube further including an outlet portion opening throughthe crown sheet and a reversely curved intermediate portion connectingsaid inlet and outlet portions, and means providing arch portionsbetween both sides of said elements and said side sheets, said archportions comprising bricks, certain ones of which are supported solelyupon said inlet portions of the tubes and others of which are supportedjointly upon said inlet portions of said tubes and upon portions of saidelement.

7. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a water steaming and circulating element in the fireboxand including a fiat hollow body arranged longitudinally of the fireboxand opening through the crown sheet, said body having a downwardly andforwardly inclined bulged bottom that merges into a tubular neck whichopens through the throat sheet of the firebox, a set of circulator tubesarranged in the firebox on each side of the water steaming andcirculating element, each set comprising a plurality of tube elementsarranged in transverse planes spaced longitudinally of the firebox, eachtube including an inlet portion, the inlet portions of all the tubes ineach set opening through the associated side sheet in a planesubstantially corresponding to the plane of the inclination of thebottom of the said body and its neck extension, each tube furtherincluding an outlet portion opening through the crown sheet and a curvedintermediate portion connecting said inlet, and transverse rows of firebrick between the inlet portions of adjacent tube elements in each set,the outer end of the brick in each row engaging an associated side sheetand the inner end of the brick in certain of the rows engaging thebottom bulge of the body and the inner end of the brick in certain otherrows engaging upon the neck extension.

8. A locomotive firebox embodying therein a crown sheet, a front sheetand side sheets, a water steaming and circulating element in the fireboxand including a fiat hollow body arranged longitudinally of the fireboxand. opening through the crown sheet, said body having a downwardly andforwardly inclined bulged bottom that merges into a tubular neck whichopens through the throat sheet of the firebox, a set of circulator tubesarranged in the firebox on each side of the water steaming andcirculating element, each set comprising a plurality of tube elementsarranged in transverse planes spaced longitudinally of the firebox, eachtube including an inlet portion, the inlet portions of all the tubes ineach set opening through the associated side sheet in a planesubstantially corresponding to the plane of the inclination of thebottom of the said body and its neck extension, each tube furtherincluding an outlet portion opening through the crown sheet and areversely curved intermediate portion connecting said inlet and outletportions, and transverse rows of fire brick between the inlet portionsof adjacent tube elements and extending from said body to the respectiveside sheets.

GUST J. CHRISTENSQN.

